William james sidis



Dec. 9, 1930.

w. J. slDls 1,784,117

PERPETUAL CALENDAR Original Filed Deo, l5 1927 Y for/700orZ`l00, use/Neif for/600, 15e /7122/ *w fr /70/-f7x/a2zayr1 )br Wiz/ZM ld /vzyr 5w: la.Tue, wed, Thu. Fri. 5w. lbf /745- add/xga /r #S0/463? if /Wyf Alan. 73e.Mir/m lh. Jaz im /Zwr AM3-186000# 685/13 v 7 far @c1-15W add .myn Hf fr75%20? Jah zym 7l/( nl 'l fbrao/a-zoes aub. /lz fj. jri 20W-zow A [M5/1MIZ/1. fr/I fat 5MM/z /e 7 7 17m rn: Jar fu. Mm we. wai

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\\\ 11i jun )lon 72u. Wed 17M. Fri. 2 3 4 5 e 7 zz 23 24 25 ze 27 asINVENTOR Patented Dec. 9, 1930 UNITED STATES WILLIAM JAMES srnls, or NEWYoan, N. Y.

PERPETUAL CALENDAR`v i original application iiled December 15, 1927,serial Nc. 240,214. Divided lami this application illed June 13, 1929.Serial No.370,713. j

This applica-tion is a division of my application No. 240,214, filedDecember 15, 1927 Patent No. 1,718,314, June 25, 1929.

The invention relates to perpetual calen- 5, dars in which week-days canbe ound diner; secondly, to avoid the cross-reference tables or complexmechanism, one or theother of which have hitherto generally beenfeatures of perpetual calendars providing means to look up the week-dayof any given date whatever; thirdly, to provide a perpetual calendar inwhich, once the calendar is adjusted for any given year, a complete andcondensed calendar for the year is at once plainly visible; ourthly, tosimplify the parts and their interrelation by the elimination ofindicators or pointers which add both to the difficulty and expense ofmanufacture and to the derangement of the operation of the calendar.

The invention is illustrated in the two figures of the accompanyingdrawing, the front sheet or card being represented in Fig. 1, and thedisk forming the remainder of the calendar being represented in Fig. 2.

The essentialfeatures of the calendar are a front sheet or card (seeFig. 1), and a disk (see Fig. 2), these two parts being attached to oneanother by means of a pivot or other rotating device whereby the diskmay be made to rotate freely about a suitable fixed point of the frontsheet.

The said disk consists of two concentric sections, the center being thepivot or axis about which the disk rotates; these two sections are themonth-section (l) and the year-V section The month-section consists oftwenty-four or more sectors, each containing the name of a month or aset of such names. At least thirteen of such sectors shall contain thenames of months arranged in the cyclical order of the week-days on whichthey begin in leap-years; and at least thirteen of such sectors shallcontain the names of months arranged in the cyclical order of theweekdays on whichlthey begin in non-leap-yea-rs; when several months ina leap-year, or in a non-leap-year as the case lnay be, begin on thesame wee -day, all such months are in the same sector.

The year-section (2) shall consist.y of a group of leap-years in sevensectors, and a" groupjof non-leap-years Y(4) in seven sectors, thesectors comprising each v'the same angle about the common center of thedisk as the month-sectors. These sectors correspond to the month-sectorsseparated from them by thesame angle ofthe disks arc that separates theinitial edge of the year-slot (5) from thator` the month-slot (6).

; All the. years within a definite period (in this'case, '1900 to1956),4 are placed in Vone of the fourteen sectors mentioned in theprecedingA paragraph, each. `such' year being placed in the leap-year ornon-leap-year sectors according as it is or is not a leap-year; and eachyear further being placed in the sector corresponding to the monthsbegin-k ning in that year on the week-day (Sunday in the instanceillustrated) found in the first row and first column of the week-daygroup (7) on the front sheet.

The front sheet (see Fig. 1) of the calendar has two perforations, amonth-slot (6) under which the month-section (1) of the disk rotates,and disclosing seven sectors'ot said month-section; and a year-slot (5)of such shape and size that, when properly adjusted, it discloses justone sector of the yearsection (2) of the disk. said sector being thatible through the month-slot.

Upon the front sheet of the calendar also is a group of week-days (7)arranged in seven rows and seven columns so that in each week appear inthe cyclical order in which they occur, and so that the continuations ofthe seven rows fit the seven month-sectors corresponding to the rstmonth-sector vis- .L29-0 row and in each column the seven days of thevisible through the month-slot (6) when the (95 disk is properlyadjusted; also a group ofV date-numbers (8) from 1 to 31, occupying thecontinuation of the seven week-day col umns, the said numbers beinglisted in succession, row by row.

ico

In addition, the front sheet of the calendar should contain aconversion-table (9), stating how many years have to he added orsubstracted in order to use the calendar for years not listed in theyear-section (2) of the disk.

The pivot (l0), or any other similar rotatory device, furnishes a meanswhereby the disk maybe rotated behind the front sheet so that the yeardesired will appear through the year-slot (the conversion-table beingused in the case of years not within the period covered on the disk).When this is done, the months appearing through the month-slot, and theweek-days and datenumhers on the front sheet, constitute a complete andcondensed calendar for the year in question, the week-day for any dateappearing in the same row as the month, and in the same column as thedate.

I claim:

The combination, in a. perpetual calendar, of a disk containing themonths properly grouped in sectors and the years occupying sectors ofthe same disk in a concentric ring; a front sheet with two slots makingvisible respectively the month-sectors and a yearsector, and containingweek-days in seven rows and seven columns, and date-numbers occupying acontinuation of those seven columns; with a pivot by means of which thedisk may be rotated at will with reference to the front sheet.

VILLIAM JAMES SIDIS.

